Stefan Behnel
BTW, I noticed that the code in typeobject.c uses "DECREF before set" two times, like this:
method_cache[h].version = type->tp_version_tag; method_cache[h].value = res; /* borrowed */ Py_INCREF(name); Py_DECREF(method_cache[h].name); method_cache[h].name = name;
Since this is so common, would it be useful to define a macro for the correct construct? Something like #define Py_SETREF(var, obj) \ { PyObject *tmp = (var); Py_INCREF(obj); \ (var) = (obj); Py_XDECREF(tmp); } Or, if we want to allow more optimizations, make two versions of it: #define Py_SETREF(var, obj) \ { PyObject *tmp = (var); Py_INCREF(obj); \ (var) = (obj); Py_DECREF(tmp); } #define Py_XSETREF(var, obj) \ { PyObject *tmp = (var); Py_INCREF(obj); \ (var) = (obj); Py_XDECREF(tmp); } Regards Antoine.